It has been well known to utilize brick cinder block and other similar materials to construct walls and it is conventional to erect a wall in courses in which the bricks or blocks in each row are spaced apart and those in the course above and below bridge the space or gap between the bricks or blocks. Most constructions such as this, utilize mortar between the joints and between the courses and depend on rigidity by the utilization of such mortar. It has also been proposed to produce walls by utilizing blocks without the use of any mortar. To this end, it has been proposed to form the blocks with protrusions and recesses as seen in the Rice patent, No. 2,826,906, and a number of forerunners, thereof, such as the Florey patent, No. 1,630,698, and Davies, No. 1,870,102. It has also been proposed to pin the blocks together and constructions of this nature are seen in Frve, No. 3,265,364, and Wilson, No. 3,759,003.